Pull more ACPI and power management updates from Rafael Wysocki: - ACPI-based device hotplug fixes for issues introduced recently and a fix for an older error code path bug in the ACPI PCI host bridge driver - Fix for recently broken OMAP cpufreq build from Viresh Kumar - Fix for a recent hibernation regression related to s2disk - Fix for a locking-related regression in the ACPI EC driver from Puneet Kumar - System suspend error code path fix related to runtime PM and runtime PM documentation update from Ulf Hansson - cpufreq's conservative governor fix from Xiaoguang Chen - New processor IDs for intel_idle and turbostat and removal of an obsolete Kconfig option from Len Brown - New device IDs for the ACPI LPSS (Low-Power Subsystem) driver and ACPI-based PCI hotplug (ACPIPHP) cleanup from Mika Westerberg - Removal of several ACPI video DMI blacklist entries that are not necessary any more from Aaron Lu - Rework of the ACPI companion representation in struct device and code cleanup related to that change from Rafael J Wysocki, Lan Tianyu and Jarkko Nikula - Fixes for assigning names to ACPI-enumerated I2C and SPI devices from Jarkko Nikula * tag 'pm+acpi-2-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (24 commits) PCI / hotplug / ACPI: Drop unused acpiphp_debug declaration ACPI / scan: Set flags.match_driver in acpi_bus_scan_fixed() ACPI / PCI root: Clear driver_data before failing enumeration ACPI / hotplug: Fix PCI host bridge hot removal ACPI / hotplug: Fix acpi_bus_get_device() return value check cpufreq: governor: Remove fossil comment in the cpufreq_governor_dbs() ACPI / video: clean up DMI table for initial black screen problem ACPI / EC: Ensure lock is acquired before accessing ec struct members PM / Hibernate: Do not crash kernel in free_basic_memory_bitmaps() ACPI / AC: Remove struct acpi_device pointer from struct acpi_ac spi: Use stable dev_name for ACPI enumerated SPI slaves i2c: Use stable dev_name for ACPI enumerated I2C slaves ACPI: Provide acpi_dev_name accessor for struct acpi_device device name ACPI / bind: Use (put|get)_device() on ACPI device objects too ACPI: Eliminate the DEVICE_ACPI_HANDLE() macro ACPI / driver core: Store an ACPI device pointer in struct acpi_dev_node cpufreq: OMAP: Fix compilation error 'r & ret undeclared' PM / Runtime: Fix error path for prepare PM / Runtime: Update documentation around probe|remove|suspend cpufreq: conservative: set requested_freq to policy max when it is over policy max ...
To understand all the Linux-USB framework, you'll use these resources:
* This source code. This is necessarily an evolving work, and
includes kerneldoc that should help you get a current overview.
("make pdfdocs", and then look at "usb.pdf" for host side and
"gadget.pdf" for peripheral side.) Also, Documentation/usb has
more information.
* The USB 2.0 specification (from www.usb.org), with supplements
such as those for USB OTG and the various device classes.
The USB specification has a good overview chapter, and USB
peripherals conform to the widely known "Chapter 9".
* Chip specifications for USB controllers. Examples include
host controllers (on PCs, servers, and more); peripheral
controllers (in devices with Linux firmware, like printers or
cell phones); and hard-wired peripherals like Ethernet adapters.
* Specifications for other protocols implemented by USB peripheral
functions. Some are vendor-specific; others are vendor-neutral
but just standardized outside of the www.usb.org team.
Here is a list of what each subdirectory here is, and what is contained in
them.
core/ - This is for the core USB host code, including the
usbfs files and the hub class driver ("khubd").
host/ - This is for USB host controller drivers. This
includes UHCI, OHCI, EHCI, and others that might
be used with more specialized "embedded" systems.
gadget/ - This is for USB peripheral controller drivers and
the various gadget drivers which talk to them.
Individual USB driver directories. A new driver should be added to the
first subdirectory in the list below that it fits into.
image/ - This is for still image drivers, like scanners or
digital cameras.
../input/ - This is for any driver that uses the input subsystem,
like keyboard, mice, touchscreens, tablets, etc.
../media/ - This is for multimedia drivers, like video cameras,
radios, and any other drivers that talk to the v4l
subsystem.
../net/ - This is for network drivers.
serial/ - This is for USB to serial drivers.
storage/ - This is for USB mass-storage drivers.
class/ - This is for all USB device drivers that do not fit
into any of the above categories, and work for a range
of USB Class specified devices.
misc/ - This is for all USB device drivers that do not fit
into any of the above categories.